More than that, because the effects were done on video the episodes were edited on video. Whichmeans if any "HD" or higher-quality versions are ever to be made the entire episodes would have to be re-edited and cut together from the filmstock.

A perfect example of how some cost-cutting measures really end up costing you more in the long run. They really blew it with this.

To be fair, no one in 1980s could have forseen home-video machines and TVs with resolutions as high as 1080.